Pot furnace for heat treating metal



Sept. 22, 1942. A. HELLER 2,296,440

POT FURNACE FOR HEAT TREATING METAL 2 Sheets-Sheet 1 Filed July 31, 1941 A; F950 fifflf/P. 7Q INVENTORT BY 5 May WITNESS" AT'Y'ORNEYI? Sept. 22, 1942. HELLER 2,296,440

POT FURNACE FOR HEAT TREATING METAL Filed July 31, 1941 2 Sheets-Sheet 2 FIG. 4

ATTORNEYS.

Patented Sept. 22, 1942 UNITED STATES PTENT OFFICE POT FURNACE FOR HEAT TREATING METAL Alfred Heller, Bloomfield, N. J.

Application July 31, 1941, Serial No. 404,792

6 Claims.

This invention relates to new and useful improvements in furnaces and more particularly it pertains to furnaces of the type employed in the heat treatment of metals and commonly known in the art as pot furnaces.

one object of the present invention is to improve the construction of furnaces of the type aforementioned thereby to render them more efficient in operation and to increase the life thereof.

A feature of the present invention resides in a novel construction of pot furnace setting whereby the heat will be uniformly applied directly to the pot of the furnace throughout the entire effective area thereof.

By reason of the fact that the heat is applied uniformly throughout the effective surface of the pot, the heating medium may be impinged directly' upon the pot without damage thereto. This is important since it makes for both higher efiiciency in operation and longer life of the pot.

Another feature of the invention resides in a novel construction of pot whereby that portion thereof which, in ordinary construction, is the first to fail, is in the present instance protected by a part which may be removed and replaced without damage to the pot itself, thus greatly prolonging the life of the pot.

Other features of the invention will become apparent as the nature of the invention is better understood and reference will now be had to the accompanying drawings wherein the invention is illustrated in a form which has in actual practice given highly satisfactory results.

In the drawings,

Figure 1 is a top plan view of a furnace constructed in accordance with the present invention,

Figure 2 is a view in elevation thereof,

Figure 3 is a horizontal sectional view on an enlarged scale taken substantially on the line 33 of Figure 2,

Figure 4 is a vertical sectional view on an enlarged scale taken substantially on the line 4-4 of Figure 1, and,

Figure 5 is a horizontal sectional view on an enlarged scale taken substantially on the line 55 of Figure 2.

In the present illustration, the invention is embodied in a furnace setting of circular form.

The furnace comprises a housing H], a combustion chamber l2, a heating gas chamber I3, and a pot chamber I4 within which is suitably mounted a pot 5!].

The housing includes a bottom wall formed preferably of two courses of brick. The brick [8 which form the lower course are of the heat insulating type, the brick 2!! which form the upper course being formed of any suitable material having high fire resistant qualities of which carborundum is one good example.

Theside walls ofthe furnace-housing consist of an inner course of fire brick 22 and an outer course of insulating brick 24, and this entire wall structure is enclosed in a metallic shell or jacket 26.

The combustion chamber 12 is preferably formed by means of a plurality of spaced baffles 23, 30, and 32 and a horizontally disposed partition wall 34, see Figure 4. These baflles 28, 30, and 32 consist of suitable carborundumblocks positioned on edge and resting upon the bottom wall of the housing. The horizontally disposed partition wall 34 is preferably formed from two slab-like elements 36 and 38 also of carborundum or other highly fire resistant material.

By reference to Figures 4 and 5, it will be apparent that the construction and arrangement just described provides a combustion chamber in the lower portion of the housing, the combustion chamber being divided by the baffle 34 into two compartments designated 40 and 42 in the drawings. Burners 44 and 46 are disposed radially of the furnace housing and project their flames respectively into the compartments 40 and 42 of the combustion chamber l2.

A concentric checker-work wall 50 constructed of fire brick is supported upon the horizontal partition 34 and extends upwardly therefrom to a height substantially equal to that of the side walls of the furnace setting.

This checker-work wall is spaced with respect to the side walls of the furnace housing and serves to divide that portion of the interior of the furnace housing above the horizontal partition 34 into the heating gas chamber l3 and the pot chamber l4 heretofore mentioned. It is circular in form and encloses the pot in spaced relation therewith and the spaces or voids designated 40 serve to provide communication between the heating gas chamber 13 and the pot chamber I4 and also to direct the heating gases into direct contact with the side walls of the pot.

The gases are carried off from the pot chamher by fiues 42. These flues may exhaust directly to atmosphere, "or they may be hooked up to any suitable stack system not herein illustrated.

The fines 42 may be constructed of tile, fire brick or the like, 44 and the metallic shell 26 may have openings 41 which register therewith as shown in Figure 4.

Resting upon, and. forming the top of the furnace setting or housing, there is a metal plate 49. This metal plate 49 has a central opening 48 which, in the present embodiment of the invention is circular in form and of a diameter substantially equal to that of the pot chamber M.

The pot is designated 50 and it consists of a cylindrical main body portion 52 having a rounded bottom wall 54, the upper end of the pot being open.

Fitted into the open upper end of the pot 50, there is a flanged ring member 56, the flange of which is designated 58. This ring member is rigidly or fixedly secured to the pot members and the flange 58 thereof rests upon the metallic plate 46 to provide means for supporting the pot '50 within the pot chamber I4 as illustrated in Figure 4.

In addition to providing supporting means for the pot, this flanged ring member performs another important function which will now be described.

Furnaces of the type herein described-are employed for treating metal in solutions of fusible salts and similar baths. In use the pot is filled with the bath to a level slightly below the open end thereof. I

In operation, oxidizing atmosphere attacks the pot walls in the area of the level of the bath and causes a failing of the walls at this point.

It has been the practice in the past to discard a pot and replace it with a new one when oxidation at the bath level begins seriously to effect the walls of the pot.

By providing a flanged ring member such as herein illustrated and in which the width of the body portion is such that its lower edge projects to a point below the operating level of the bath, such oxidation as takes place at the bath level reacts upon the body portion of the flanged ring instead of upon the side wallsof the pot.

By the construction employed, it will be obvious that the flanged ring member provides a protection for the side wallsof thepot at the bath level and that when deterioration of the ring member renders it useless, it may be removed from the pot and another flanged ring member substituted therefor.

While the invention has been herein illustrated in its preferred form, it is to be understood that it is not to be limited to the specific construction a 7 herein shown and that it may be embodied in such other forms as rightfully fall within the scope of the appended claims.

Having thus described the invention, what I claimas new is:

1. va furnace of the type described in combination, a furnace housing, a pot supported within the'furnacehousing, a checker work wall surrounding the pot in spaced relation thereto and dividing the interior of the furnace'housing into a pot chamber-and a gas chamber having communication with each other throughout the entire height of the'checker-work' wall through the voids or spaces thereof and means for supplying heating gases to the gas chamber.

2. In a furnace .of the type described in combination, a furnace housing, :a horizontal partition spaced withrespect to the bottom wall of the housing and having itsside. edges spaced from the side walls of the housing to form a combustion chamber below the plane of the horizontal partition, means for supporting the horizontal partition in position and for dividing the combustion chamber into compartments, a checkerwork wall extendingv upwardly from the side edges 3. In a furnace of the type described in combination, a furnace housing, a horizontal partition spaced with respect to the bottom wall of the housing to form a combustion chamber, means for supporting the horizontal partition in position and for dividing the combustion chamber into compartments, a checker-work wall supported upon said horizontal partition, said checker work'wall dividing the upper portion of the furnace housing into a gas chamber having communication with the combustion chamber and a pot chamber, and a pot suspended within the pot chamber and extending throughout the major portion of the height of the checker-wall.

4. In a furnace of the type described in combination, a housing, a pot, means for supporting the pot within the housing, baffles dividing the lower portion of the housing into a combustion chamber, a checker-work wall cooperating with the outer wall of the housing to divide that portion thereof above the combustion chamber into a gas chamber having communication with the combustion chamber and providing in itself a pot chamber in which the pot is positioned, said checker-work wall extending throughout the effective length of the pot, and take-off flues leading from the pot chamber.

5. A furnace of. the type described comprising in combination, a circular furnace housing, a plurality of parallel bafiies upon the bottom wall of the housing, a horizontally disposed circular partition supported upon said baflies and forming with the bafiies a divided combustion chamber in the lower portion of the furnace housing, a continuous circular checker-work wall supported .upon the horizontal partition, said checkerwork wall dividing the upper portion of the furnace housing into an annular heating gas chamber having communication with the combustion chamber and a pot chamber having communication with the annular heating gas chamber through the spaces or voids of the checker-work wall, a pot within the pot chamber and spaced with respect to the walls thereof, and means 'for generating heating gases in the combustion chamber.

6. In a furnace of the'type described in combination, a furnace housing, a horizontal partition of lesser transverse'dimensions than the inner transverse dimensions of the housing located in the lower portion of the housing in spaced relation thereto to provide a combustion chamber in the bottom of the housing, means for supporting said horizontal partition in spaced relation to the bottom wall of the housing and for dividing the combustion chamber into compartments, a checker-work wall supported upon said horizontal partition and extending vertically therefrom, the checker-work wall dividing that portion of the furnace housing above the horizontal partition into a heating gas chamber having direct communication with the combustion chamber and. a pot chamber having communication with the heating gas chamber only through the voids of the checker-work wall, a pot supported in the pot chamber with its bottom wall in spaced rel-ation with said horizontal partition, and fiues leading from the upper portion of the pot chamber from points above the top wall of thechecker- Work wall,

ALFRED HELLER. 

